However I do strongly feel that touchscreen is the opposite to productivity, maybe usability to the end users, but definitely not what developers need/want.
I agree it's less productive on its own, but it works well when used as a hybrid where you have two types of pointers on one screen.
I may not prefer touch screens but they can be a complete game changer for some users.
Vertical touch screens trade the more traditional wrist/elbow strain/RSIs for other arm/elbow/shoulder strain/RSIs (including things like "gorilla arm").
Given the nature of repetitive stress, the growing consensus seems to be not that one orientation is better than the other, but that a range of orientations, and a mixture of movement types / input methods is better. For instance, move your arm some to touch a vertical screen, to mix things up from mouse movements and keyboard movements.